security_content/detections/endpoint/linux_curl_upload_file.yml at fdaa038eab70c41517d8e8290c4f522154b7e238 · splunk/security_content · GitHub

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name: Linux Curl Upload File
id: c1de2d9a-0c02-4bb4-a49a-510c6e9cf2bf
version: 5
date: '2024-11-13'
author: Michael Haag, Splunk
status: production
type: TTP
description: The following analytic detects the use of the curl command with specific
  switches (-F, --form, --upload-file, -T, -d, --data, --data-raw, -I, --head) to
  upload AWS credentials or configuration files to a remote destination. This detection
  leverages data from Endpoint Detection and Response (EDR) agents, focusing on command-line
  executions and process details. This activity is significant as it may indicate
  an attempt to exfiltrate sensitive AWS credentials, a technique known to be used
  by the TeamTNT group. If confirmed malicious, this could lead to unauthorized access
  and potential compromise of AWS resources.
data_source:
- Sysmon for Linux EventID 1
search: '| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time)
  as lastTime from datamodel=Endpoint.Processes where Processes.process_name=curl
  Processes.process IN ("*-F *", "*--form *","*--upload-file *","*-T *","*-d *","*--data
  *","*--data-raw *", "*-I *", "*--head *") AND Processes.process IN ("*.aws/credentials*".
  "*.aws/config*") by Processes.dest Processes.user Processes.parent_process_name
  Processes.process_name Processes.process Processes.process_id Processes.parent_process_id
  | `drop_dm_object_name(Processes)` | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`
  | `linux_curl_upload_file_filter`'
how_to_implement: The detection is based on data that originates from Endpoint Detection
  and Response (EDR) agents. These agents are designed to provide security-related
  telemetry from the endpoints where the agent is installed. To implement this search,
  you must ingest logs that contain the process GUID, process name, and parent process.
  Additionally, you must ingest complete command-line executions. These logs must
  be processed using the appropriate Splunk Technology Add-ons that are specific to
  the EDR product. The logs must also be mapped to the `Processes` node of the `Endpoint`
  data model. Use the Splunk Common Information Model (CIM) to normalize the field
  names and speed up the data modeling process.
known_false_positives: Filtering may be required. In addition to AWS credentials,
  add other important files and monitor. The inverse would be to look for _all_ -F
  behavior and tune from there.
references:
- https://curl.se/docs/manpage.html
- https://www.cadosecurity.com/team-tnt-the-first-crypto-mining-worm-to-steal-aws-credentials/
- https://gtfobins.github.io/gtfobins/curl/
drilldown_searches:
- name: View the detection results for - "$user$" and "$dest$"
  search: '%original_detection_search% | search  user = "$user$" dest = "$dest$"'
  earliest_offset: $info_min_time$
  latest_offset: $info_max_time$
- name: View risk events for the last 7 days for - "$user$" and "$dest$"
  search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$user$",
    "$dest$") starthoursago=168  | stats count min(_time) as firstTime max(_time)
    as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk
    Message" values(analyticstories) as "Analytic Stories" values(annotations._all)
    as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics"
    by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`'
  earliest_offset: $info_min_time$
  latest_offset: $info_max_time$
rba:
  message: An instance of $process_name$ was identified on endpoint $dest$ by user
    $user$ attempting to upload important files to a remote destination.
  risk_objects:
  - field: user
    type: user
    score: 64
  - field: dest
    type: system
    score: 64
  threat_objects:
  - field: process_name
    type: process_name
tags:
  analytic_story:
  - Linux Living Off The Land
  - Data Exfiltration
  - Ingress Tool Transfer
  asset_type: Endpoint
  mitre_attack_id:
  - T1105
  product:
  - Splunk Enterprise
  - Splunk Enterprise Security
  - Splunk Cloud
  security_domain: endpoint
tests:
- name: True Positive Test
  attack_data:
  - data:
      https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1105/atomic_red_team/curl-linux-sysmon.log
    source: Syslog:Linux-Sysmon/Operational
    sourcetype: sysmon:linux